The present invention relates to a method and structure of a cable assembly with electromagnetic interference protection and especially to a method and structure of a liquid crystal display cable assembly with electromagnetic interference protection.
Information technology and the computer industry are highly developed now. Portable electronic devices, and especially notebook computers, are used more popularly. Notebook computers are becoming increasingly smaller, and so the electronic parts thereof must be reduced in size and the operating speed thereof enhanced. The display area of the liquid crystal display (LCD), however, needs to be enlarged for the user.
Normally, an LCD cable is necessary for power and signal transmission between the motherboard and the LCD in a notebook computer. Due to the LCD cable connecting the motherboard and the LCD, electromagnetic interference (EMI) noises of the motherboard radiate from the LCD cable. A shield is designed for preventing the EMI noises to eliminate the EMI noise generated by the electromagnetic wave; LCD interference is consequently reduced and the operating system works more smoothly. One end of the LCD cable must connect with the ground of the computer to dissipate the electromagnetic interference.
FIG. 1 is a schematic view of a traditional LCD cable with a ground cable. A traditional LCD cable 100 has a transmission cable 130 and a ground cable 120. The transmission cable 130 connects with the motherboard of a computer and the LCD to transfer power and data thereto. The ground cable 120 transfers EMI noise to the ground of the computer to eliminate the disturbance by the EMI noises. Normally, the LCD cable 100 couples with the ground of the computer by way of a ground terminal 110 attached to the end of the ground cable 120. The ground terminal 110 is usually clamped on the ground cable 120.
FIG. 2 is a schematic view of the traditional LCD cable installed on a metal fixing plate of a notebook computer. As the drawing shows, a plurality of clips 220 is mounted on the metal fixing plate 210 for fastening the transmission cable 130 of the LCD cable 100. The ground cable 120 is directly screwed on the metal fixing plate 210 with a fixing bolt 230. The metal fixing plate 210 directly connects with the ground of the computer. Therefore, the ground cable 120 delivers the EMI noise to the ground of the computer by way of the metal fixing plate 210.
The conventional computer fulfills the EMI specification because the LCD cable 100 can transmit the EMI noises to the ground of the computer but the ground terminal 110 attached to the end of the ground cable 120 is screwed on the metal fixing plate 210 by the fixing bolt 230 when the computer is assembled. The fixing bolt 230 is unscrewed to release the ground terminal 110 when the LCD cable 100 is removed from the metal fixing plate 210 of the computer. Assembly time thus increases due to the screwing process. Repair time for the computer also increases if the fixing bolt 230 needs to be unscrewed during the repair process, and especially if the fixing bolt 230 is repeatedly screwed and unscrewed during the repair process. Repair process time is further increased because the fixing bolt 230 must be checked and distinguished from the other bolts removed during the repair process. Furthermore, if the ground cable 120 gets loose from the metal fixing plate 210 or the ground terminal 110, the ground cable 120 may touch the motherboard of the computer to cause a short or seriously damage the computer. Therefore, the ground cable has to be secure on the metal fixing plate of the computer, connect with the ground of the computer, reduce installation and removal time, and efficiently avoid the ground cable getting loose from the ground terminal.
One object of the present invention is to utilize a metal ring to fix the transmission cable and the ground cable, whereby the ground cable can utilize a clip made of a conductive material to transmit the EMI noise to the ground of the computer.
Another object of the present invention is to utilize the metal ring to simplify the computer assembly process and especially the computer repair process.
A further object of the present invention is to secure the transmission cable and the ground cable together to avoid the ground cable contacting other electronic parts and reduce the risk while the computer is working.
The present invention provides an assembly method of a cable with electromagnetic interference protection for an electric appliance, such as a notebook computer. The method comprises the following steps. First, conductive clips are connected with a ground circuit of the electric appliance. Second, at least one position of an insulating layer of a ground wire of the cable is peeled off to expose an internal conductive metal wire. The exposed position corresponds to the conductive clip position. Then, at least one metal ring is used to fix the position of the ground wire and a transmission wire of the cable. Finally, the metal ring, the transmission wire, and the ground wire arc pressed into the conductive clips to fix the cable in the conductive clips and to connect the internal conductive metal wire with the ground circuit of the electric appliance.
The cable includes a liquid crystal display cable to connect the liquid crystal display and the motherboard of a notebook computer. The cable transmits a power and signals between the liquid crystal display and the motherboard of the notebook computer. The internal conductive metal wire connects with the ground circuit of the electric appliance to transmit electromagnetic interference (EMI) noises to the ground circuit of the electric appliance.
Another aspect of the present invention is to provide a cable with electromagnetic interference protection for an electric appliance. The cable comprises a plurality of conductive clips, a transmission wire, a ground wire, and at least one metal ring. The conductive clips are mounted on a fixing plate of the electric appliance and the conductive clips connect with a ground circuit of the electric appliance. The transmission wire connects a plurality of elements of the electric appliance. The ground wire has at least one contact position of an insulating layer of the ground wire of the cable. The contact position exposes an internal conductive metal wire and the contact position corresponds to the conductive clip position. The metal ring clasps the transmission wire and the ground wire at the contact position to connect the metal ring with the internal conductive metal wire.
The conductive clips are made of metal material. The cable comprises a liquid crystal display cable to transmit power and signals between a liquid crystal display and a motherboard of a notebook computer. The internal conductive metal wire connects with the ground circuit of the notebook computer to transmit electromagnetic interference (EMI) noise to the ground circuit of the notebook computer.
Therefore, the cable according to the present invention connects the ground of the electric appliance efficiently, simplifies the assembly process, avoids the ground getting loose, and increases the efficiency of the repair process.